Note 44 — PART I. MENSTRUATION.

“In the human female, the period of puberty, or of commencing aptitude for procreation, is usually between the thirteenth and sixteenth years. It is generally thought to be somewhat earlier in warm climates than in cold, and in densely populated manufacturing towns than in thinly populated agricultural districts. The mental and bodily habits of the individual have also considerable influence upon the time of its occurrence; girls brought up in the midst of luxury or sensual indulgence undergoing this change earlier than those reared in hardihood and self-denial.”—Dr. Carpenter’s Human Physiology.